Methicillin-resistant Staphylococcus aureus and extended-spectrum and AmpC β-lactamase-producing Escherichia coli in broilers and in people living and/or working on organic broiler farms
Introduction
Human infections with methicillin-resistant Staphylococcus aureus (MRSA), and extended-spectrum and AmpC β-lactamase (ESBL/AmpC)-producing Escherichia coli have both been associated with reservoirs in livestock (van Loo et al., 2007, Carattoli, 2008). This raises a public health concern as transmission could occur between animals and humans. Livestock-associated (LA)-MRSA and ESBL/AmpC-producing E. coli have been found in broilers, and in individuals working and/or living on conventional Dutch broiler farms (Dierikx et al., 2013, Geenen et al., 2013, Huijbers et al., 2014). The prevalences of MRSA and ESBL/AmpC-producing E. coli are higher in humans on these farms than in the community (Bode et al., 2011, Geenen et al., 2013, Huijbers et al., 2013, Huijbers et al., 2014), and contact with live broilers has been identified as a risk factor for human carriage (Mulders et al., 2010, Huijbers et al., 2014).
In comparison to conventional farms, organic broiler farms have lower flock densities, different breeds, restrictions in antimicrobial use, availability of outdoor areas, and later slaughter age. These factors could lead to a lower prevalence of MRSA and ESBL/AmpC-producing E. coli among broilers on organic compared to conventional farms, and might also affect carriage of humans. There are currently no studies investigating carriage of MRSA and ESBL/AmpC-producing E. coli among humans and broilers on organic farms. The aim of this study was to estimate the prevalence of MRSA and ESBL/AmpC-producing E. coli among broilers, and humans living and/or working on organic broiler farms; further characterise isolates from humans and broilers; and compare these results with those from conventional farms.
Section snippets
Study population
From October 2011 to April 2012 a prevalence study for MRSA and ESBL/AmpC-producing E. coli was conducted on 8 out of 9 certified organic broiler farms in the Netherlands. Certified organic broiler farms are those that comply with legal regulations laid down by the European Commission. Chapter 2 of Commission Regulation No. 889/2008 describes production rules for different livestock species, including broilers (EC, 2008). Participating farms had a median of 1.5 broiler houses (range 1–22) and
Descriptive statistics
In total, 27 out of 36 individuals agreed to participate. These participants included 9 farmers, 16 family members, and two employees. Per farm, this ranged from two to seven individuals, with an average age of 40.6 years (range 4–76 years).
MRSA-carriage among broilers and humans
MRSA was not detected in all 80 pooled throat swabs and 120 environmental wipes, so all farms were classified MRSA-negative. The prevalence of positive organic farms (0/8) was not statistically different (P = 1.0) from conventional farms (4/50; Geenen et al.,
Conclusion
MRSA was not detected in broilers or humans on Dutch organic broiler farms. In contrast, ESBL/AmpC-producing E. coli were detected in broilers on all farms, with a prevalence of ≥80% at the sample-level, and in 18.5% of humans. Given the higher prevalence of ESBL/AmpC-producing E. coli among humans living and/or working on organic farms compared to the general Dutch population and similarity to the prevalence in humans on conventional farms, contact with live broilers could also be a risk
Conflict of interest
None declared.
Acknowledgements
This work was financially supported by the Netherlands Food and Consumer Product Authority (NVWA) (grant number V330091). We would like to thank all farmers, their family members and employees for participating in this study.
References (21)
- et al.
Sustained low prevalence of methicillin-resistant Staphylococcus aureus upon admission to hospital in The Netherlands
J. Hospital Infect.
(2011) Animal reservoirs for extended spectrum β-lactamase producers
Clin. Microbiol. Infect.
(2008)- et al.
Comparison of ESBL contamination in organic and conventional retail chicken meat
Int. J. Food Microbiol.
(2012) - et al.
Prevalence of extended-spectrum β-lactamase-producing Enterobacteriaceae in humans living in municipalities with high and low broiler density
Clin. Microbiol. Infect.
(2013) - et al.
Transmission of ESBL/AmpC-producing Escherichia coli from broiler chicken farms to surrounding areas
Vet. Microbiol.
(2014) - et al.
Extended-spectrum-β-lactamase-and AmpC-β-lactamase-producing Escherichia coli in Dutch broilers and broiler farmers
J. Antimicrob. Chemother.
(2013) Commission Regulation (EC) No. 889/2008 of 5 September 2008 laying down detailed rules for the implementation of Council Regulation (EC) No. 834/2007 on organic production and labelling of organic products with regard to organic production, labelling and control
Official Journal of the European Union
(2008)- et al.
Prevalence of livestock-associated MRSA on Dutch broiler farms and in people living and/or working on these farms
Epidemiol. Infect.
(2013) - et al.
Extended-spectrum and AmpC beta-lactamase-producing Escherichia coli in broilers and people living and/or working on broiler farms: prevalence, risk factors and molecular characteristics
J. Antimicrob. Chemother.
(2014) - et al.
Overlapped sequence types (STs) and serogroups of avian pathogenic (APEC) and human extra-intestinal pathogenic (ExPEC) Escherichia coli isolated in Brazil
PLOS ONE
(2014)
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